Take instrumentation overhead into account when plotting.

src/log.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 689 matching lines @@
   msg.Append("shared-library,\"%ls\",0x%08" V8PRIxPTR ",0x%08" V8PRIxPTR "\n",
              library_path,
              start,
              end);
   msg.WriteToLogFile();
 }
 
 
 void Logger::TimerEvent(const char* name, int64_t start, int64_t end) {
   if (!log_->IsEnabled()) return;
-  ASSERT(FLAG_log_timer_events);
+  ASSERT(FLAG_log_internal_timer_events);
   LogMessageBuilder msg(this);
   int since_epoch = static_cast<int>(start - epoch_);
   int pause_time = static_cast<int>(end - start);
   msg.Append("timer-event,\"%s\",%ld,%ld\n", name, since_epoch, pause_time);
   msg.WriteToLogFile();
 }
 
 
 void Logger::ExternalSwitch(StateTag old_tag, StateTag new_tag) {
   if (old_tag != EXTERNAL && new_tag == EXTERNAL) {
@@ skipping 651 matching lines @@
 }
 
 
 void Logger::TickEvent(TickSample* sample, bool overflow) {
   if (!log_->IsEnabled() || !FLAG_prof) return;
   LogMessageBuilder msg(this);
   msg.Append("%s,", kLogEventsNames[TICK_EVENT]);
   msg.AppendAddress(sample->pc);
   msg.Append(',');
   msg.AppendAddress(sample->sp);
-  msg.Append(",%ld",
-      FLAG_log_timer_events ? static_cast<int>(OS::Ticks() - epoch_) : 0);
+  msg.Append(",%ld", static_cast<int>(OS::Ticks() - epoch_));
   if (sample->has_external_callback) {
     msg.Append(",1,");
     msg.AppendAddress(sample->external_callback);
   } else {
     msg.Append(",0,");
     msg.AppendAddress(sample->tos);
   }
   msg.Append(",%d", static_cast<int>(sample->state));
   if (overflow) {
     msg.Append(",overflow");
@@ skipping 387 matching lines @@
   Isolate* isolate = Isolate::Current();
   ticker_ = new Ticker(isolate, kSamplingIntervalMs);
 
   if (FLAG_sliding_state_window && sliding_state_window_ == NULL) {
     sliding_state_window_ = new SlidingStateWindow(isolate);
   }
 
   bool start_logging = FLAG_log || FLAG_log_runtime || FLAG_log_api
     || FLAG_log_code || FLAG_log_gc || FLAG_log_handles || FLAG_log_suspect
     || FLAG_log_regexp || FLAG_log_state_changes || FLAG_ll_prof
-    || FLAG_log_timer_events;
+    || FLAG_log_internal_timer_events;
 
   if (start_logging) {
     logging_nesting_ = 1;
   }
 
   if (FLAG_prof) {
     profiler_ = new Profiler(isolate);
     if (!FLAG_prof_auto) {
       profiler_->pause();
     } else {
       logging_nesting_ = 1;
     }
     if (!FLAG_prof_lazy) {
       profiler_->Engage();
     }
   }
 
-  if (FLAG_log_timer_events) epoch_ = OS::Ticks();
+  if (FLAG_log_internal_timer_events || FLAG_prof) epoch_ = OS::Ticks();
 
   return true;
 }
 
 
 void Logger::SetCodeEventHandler(uint32_t options,
                                  JitCodeEventHandler event_handler) {
   code_event_handler_ = event_handler;
 
   if (code_event_handler_ != NULL && (options & kJitCodeEventEnumExisting)) {
@@ skipping 111 matching lines @@
 void SamplerRegistry::RemoveActiveSampler(Sampler* sampler) {
   ASSERT(sampler->IsActive());
   ScopedLock lock(active_samplers_mutex);
   ASSERT(active_samplers_ != NULL);
   bool removed = active_samplers_->RemoveElement(sampler);
   ASSERT(removed);
   USE(removed);
 }
 
 } }  // namespace v8::internal